Lead cable press



Dec. 3, 1929. K. SCHROTT 1,737,773.

' LEAD CABLE PRESS File d 'Feb. 29. 1928 Patented 3, 19 29 UNITED STATES"PATENT OFFICE KASIMIR SCHROTT, OF MAGDEBURG, GERMANY, ASSIGNOIB Tb THEFIRM FRIED. KRUPP GBUSONWEBK AKTIEHGESELLSQHAFT, F MAGDEBUBG-BUCKAU,GERMANY mm CABLE rinse Application ma reunite," 1928 Serial No. 258,124,and in Germany mantis, 1927.

This invention relates to lead cable presses. In order to sheath cablesof difierent diameters with one and the same press, hitherto all thepressing heads have had to be changed. This changing of the pressingheads, however, is a very tedious process and requires time, thusentailing a substantial increase in the cost of working. In order toobviate this drawback attempts have already been made in connection withthe sheathing of both thin and thick cables to work with only one presshead by using different mandri-lholders adapted, as regardstheir innerdiameter,

to the actual diameter of the cable to be sheathed. The result of theseattempts however has been that with an increasing difi'erence betweenthe external diameter of the mandril holder and the inner diameter ofthe mandril the further screwin in of the mandril holder, necessary forre ucing the thickness of the lead sheath, becomes increasinglydiflicult owing to the increasing pressure and friction surface, andfinally-it cannot beeffected at all when the press has once beensub'ectcd to pressure and consequently has lea in its lead chamber. Thislatter drawback also occurs in particular when a relatively thin cablehas to be sheathed, because in this case the annular-surface of themandril holder with mandril, working in opposition to the lead containedin the lead chamber, has to be very large.

In order to overcome the drawbacks men 'tioned above, at least one ofthe mandril holders is, according to the present invention soconstructed that there can be inserted therein a second mandril holder"intended for the rece tion of a thinner cable than that ordinariFyreceived by the first mandril holder, thus rendering it possible toeffect a relatively easy adjustment of the mandril holder even in thecase of a great diflt'erence between its external diameter and the innerdiameter of the mandril. v

It is especially advantageous, as mentioned again hereinafter, toconstruct the mandril holders so that the are divided transversely inrelation to their ongitudinal axes.

In order that the said'invention may be clearly understood and readilycarried into effect the same will now be describedmore fully withreference to the accompanying drawings which illustrate two pressingheads of a vertical lead cable press and in which Figure 1 is a verticalsection taken through .the central axis of the mandril holder.

Figure 2 is a vertical section corresponding to Figure 1 but showing asecond mandril with the mandril 7. With the dimensions in: I

dicated in Figure 1 for the inner diameter of the parts, the press headis arranged for sheathing or covering a relatively thick cable.

' If now a thin cable is to be sheathed, the mandril holder 6 is takenout and upon it, in place of the mandril 7, there is fitted anadjustment member 8 and into the mandril holder 6 which is provided withan internal screw thread 6 there is screwed a second mandril holder 9with its mandril 10, the bore of both of which is suchas to correspondto the thickness of the thinner cable that is now to be sheathed. Afterthe matrix holder 3 has also becamevided with an insertion member l' anda matrix '5' of smaller bore the pressing process can be commenced. Thenecessary adjustment between the mandril 10 and the matrix 5', for thepurpose of fixing precisely the thickness of the lead sheath, is noweffected.

solely by displacing the mandril holder v9. If instead of the twomandril holders 6, 9 only a single mandril holder were provided, thenowing to the large annular cross section working in opposition to thelead in the lead chamber the screwing-in of this mandril holder would bepractically impossible. The man-- dril holder 9, on the contrary, worksmerely with a relatively small annular cross section upon the leadcontained in the lead chamber and can, consequently, be screwed intoposition without "difiiculty, while the mandrll holder 6 rests with itshead upon the pressing head and remains stationary.

The mandril holders are preferably divided transversely in relation totheir longitudinal axes, as a result of which a further reduction in thework entailed in screwing the mandril holder into position is effected.If a lead cable press has during a pressing process once been subjectedto the very high pressure usual with such presses, then a rotation ofthe parts in intimate contact with the lead is only rendered possiblewith a maximum expenditure of labour. This is due to the strong adhesionof the lead and more especially to the lead forcing its way between themandril holden and the pressing head. A mere displacement however of themandril holder involves, in comparison with a displacement by rotation,a su stantial simplification of the operation. In Figure 3 the mandrilholders .are shown divided. Upon rotation of one of the external parts11 or 12 of the mandril holder, the inside parts 13 and 14 (so-calledcartridges) do not participate, so that the conical surfaces of themandril or of the mandril holder coming in contact with the lead do notrotate but are only displaced axially. The friction between the annularsurfaces of the-two mandril holder parts is relatively slight and canthus be easily overcome. In order to withdraw the cartridges from thepressing head they are provided with an inner screw thread 13' or 14into which'a bolt can be screwed when they are to be withdrawn.

In the claims which follow the terms relatively large and relativelysmall are used to compare the inner diameter of the outer mandril holderwith the inner diameter of the inner mandril holder. 1

Having now particularly described and as certained the nature ofiny saidinvention and in what manner the same is to be performed, I declare thatwhat I claim is:-

1. In a lead cable press, a press head, a die mounted therein, a mandrilholder 'of rela-' tively large inner diameter mounted in said press headso as to be adjustable toward and from said die, and a second mandrilholder of relatively small inner diameter adjustably gountedwithin saidfirst mentioned mandril older.

2. In a lead cablepress, the combination 4 with a mandril holder ofrelatively large inner diameter of a second mandril holder fittingwithin the first and adjustable relative thereto. I

KASIMIR SCHROTT.

